Processing of substrates using ions finds several applications including ion beam etching and ion implantation. Ion implantation is a standard technique for introducing property-altering impurities into substrates. During a typical ion implantation process, a desired impurity material is ionized in an ion source, the ions are accelerated to form an ion beam of prescribed energy, and the ion beam is directed at the surface of a substrate. The energetic ions in the ion beam penetrate into the sub-surface of the substrate material and are embedded into the crystalline lattice of the substrate material to form a region of desired conductivity or material property.
A processing apparatus that uses ions to treat a substrate may extract ions from a plasma to perform etching, ion implantation or other process. This may generate an ion beam having a roughly circular or elliptical cross sectional shape, an elongated ribbon shape, or other shape that is smaller than the surface of a substrate to be treated. In order to direct ions over substantially the entire surface of the substrate, the substrate may be mechanically driven or “scanned” in a direction that is orthogonal to the direction of an ion beam projected thereon. For example, if an ion beam is projected along a horizontal plane toward a vertically-oriented substrate, the substrate may be scanned in a vertical direction and/or in a lateral direction that is perpendicular to the projected ion beam. The entire surface of the substrate may thereby be exposed to the relatively smaller ion beam during an implantation process.
It is generally desirable to minimize the physical size of a processing apparatus in order to efficiently utilize space within a manufacturing environment. However, this preference for smaller processing apparatus may be balanced against a need for increasing size of substrates such as semiconductor substrates, as well as the requirement that a process chamber of a processing apparatus is generally at least twice as large in one dimension as a substrate to be treated so that the entire surface of the substrate can be scanned across a projected ion beam.
It is with respect to these and other considerations that the present improvements have been needed.